How to reliably get dependent variable name from formula object?

Question

Let\'s say I have the following formula:

myformula<-formula(\"depVar ~ Var1 + Var2\")

How to reliably get dependent variable name from formu

Answer 1

This should always give you all dependent vars:

myformula<-formula("depVar1 + depVar2 ~ Var1 + Var2")
as.character(myformula[[2]])[-1]
#[1] "depVar1" "depVar2"

And I wouldn't consider this particularly "hacky".

Edit:

Something strange happens with 3 dependents:

myformula<-formula("depVar1 + depVar2 + depVar3 ~ Var1 + Var2")
as.character(myformula[[2]])
#[1] "+"                 "depVar1 + depVar2" "depVar3" 

So this might not be as reliable as I thought.

Edit2:

Okay, myformula[[2]] is a language object and as.character seems to do something similar as languageEl.

length(myformula[[2]])
#[1] 3
languageEl(myformula[[2]],which=1)
#`+`
languageEl(myformula[[2]],which=2)
#depVar1 + depVar2
languageEl(myformula[[2]],which=3)
#depVar3
languageEl(languageEl(myformula[[2]],which=2),which=2)
#depVar1

If you check the length of each element, you could create your own extraction function. But this is probably too much of a hack.

Edit3: Based on the answer by @seancarmody all.vars(myformula[[2]]) is the way to go.